It is used withing sfFilebasePlugin, take a look there to see how it works. Or examine the source widgets, there are many options to let this plugin be highly configurable. A tiny example reveals the README file.

Developers

License

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

sfWidgetFormInputSWFUploadPlugin

This plugin is now an required dependancy of sfFilebasePlugin. See at its
sample project to see it in action.

Instructions:

Use the widget like an ordinary file upload widget and configure it by
passing custom options to its options array.

In custom form you'd to probably manually include the widgets assets (javascripts
and stylesheets). Do so by using $myform->getJavascripts() and
$myform->getStylesheets().

Please refer to the source file
(plugins/sfWidgetFormInputSWFUploadPlugin/lib/widget/sfWidgetFormInputSWFUPload.php)
and study the possible widget's options.

Note that the widget uses flash to perform the file upload. That means that the
form that wraps the widget will never be submitted by your webbrowser. You may
simulate a form submission by setting the option "send_serialized_values". This
forces the upload widget to serialize all form values and to send them as
additional parameters towards your upload service. This may not be the required
behaviour because the serialized data will be send within each server request,
which means each file beeing uploaded.